William Howell may refer to:
- Bill Howell (cricketer) (1869–1940), Australian cricketer
- William Howell (cricketer, born 1902) (1902–1987), Australian cricketer
- William Howell (cricketer, born 1883) (1883–1960), New Zealand cricketer
- William Howell (Barbadian cricketer) (1866-1958), Barbadian cricketer
- William Devin Howell (born 1970), American serial killer
- William G. Howell (born 1971), American political scientist
- William Henry Howell (1860–1945), American physiologist
- William J. Howell (born 1943), American politician
- William R. Howell, former chairman and CEO of J.C. Penney Company, Inc
- William Roe Howell (1846–1890), New York City photographer
- William Thompson Howell (1810–1870), American jurist and politician
- William Tudor Howell, British Conservative politician, MP for Denbigh Boroughs
- William Terry Howell, for whom a Liberty ship was named
- William Howell (rugby union) (1863–?), Welsh rugby union player
- William D. Howell (1797–1836), American surgeon who died as a defender of the Alamo
- William Barberie Howell (1865–1927), judge for the United States Customs Court